Railroad Archives Online
- CollectionE0437 - Jim Parker Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- Item48076 - Northern Pacific Caboose Number 1015 and Northern Pacific Freight Car 15593, Ellensburg, Washington, 1967
- Item48077 - Northern Pacific Caboose Number 1119, Sprague, Washington, 1967
- Item48078 - Northern Pacific Caboose Number 1398, Saint Cloud, Minnesota, 1967